v144 · css

Respect overscroll-behavior for keyboard scrolls

When you set `overscroll-behavior` to a value other than `auto`, the browser should not perform scroll chaining. We respect this for mouse or touch scrolling, however keyboard scrolls were ignoring it. This change makes keyboard scrolling respect overscroll-behavior as well.

concepts

  1. Keyboard Overscroll

    overscroll-behavior now applies to keyboard scrolling, not just touch and wheel. Modals and sticky overlays stay properly contained when the user uses arrows or Page keys.

  2. Modal Keyboard Trap

    Tab into a modal scroller, hold Page Down. v144 stops the outer page from scrolling once the modal hits its end via the keyboard.

  3. Input Modes Lab

    All three input modes — wheel, touch, keyboard — on the same nested scroller. Watch which one chains and which one doesn't, depending on overscroll-behavior.

  4. Values Explorer

    Side-by-side boxes with auto, contain, and none — tab into each and press ↓ or Page Down to verify Chrome 144's keyboard-scroll containment. Includes nested-scroller chain tests and a reference matrix.

why it shipped

Using overscroll-behavior helps authors avoid user confusion when scrolling in components that feel disconnected from their ancestor scrolling. By preventing non-local side effects, it provides a more predictable experience.

references